The chief purpose of propaganda is to influence, sway or the mental inclination of a target audience, or the minds of a particular set of people to accept a particular perspective to a story, or communicate pre-fabricated information.
Usually, propaganda is a political strategy often deployed by people who have some measure of influence over the media.
Perfect fifth because you are going from do to so which is 5 steps apart :) so do to ti would be a perfect seventh since theyre seven steps apart. a perfect octave would be do to do.